docs: def _set_annotation_to_str(annotation_data: Mapping[str, Mapping[str, bool]], key: str) -> str:
      """Return a set annotation string."""
      value = annotation_data[key]
  
      if len(value) == 1:
          return 'SET {} = "{}"'.format(key, list(value)[0])
  
      x = ('"{}"'.format(v) for v in sorted(value))
  
      return 'SET {} = {{{}}}'.format(key, ', '.join(x))